diff options
Diffstat (limited to 'arch/ia64/kernel/smpboot.c')
| -rw-r--r-- | arch/ia64/kernel/smpboot.c | 692 |
1 files changed, 692 insertions, 0 deletions
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c new file mode 100644 index 00000000000..5318f0cbfc2 --- /dev/null +++ b/arch/ia64/kernel/smpboot.c @@ -0,0 +1,692 @@ +/* + * SMP boot-related support + * + * Copyright (C) 1998-2003 Hewlett-Packard Co + * David Mosberger-Tang <davidm@hpl.hp.com> + * + * 01/05/16 Rohit Seth <rohit.seth@intel.com> Moved SMP booting functions from smp.c to here. + * 01/04/27 David Mosberger <davidm@hpl.hp.com> Added ITC synching code. + * 02/07/31 David Mosberger <davidm@hpl.hp.com> Switch over to hotplug-CPU boot-sequence. + * smp_boot_cpus()/smp_commence() is replaced by + * smp_prepare_cpus()/__cpu_up()/smp_cpus_done(). + */ +#include <linux/config.h> + +#include <linux/module.h> +#include <linux/acpi.h> +#include <linux/bootmem.h> +#include <linux/cpu.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/kernel_stat.h> +#include <linux/mm.h> +#include <linux/notifier.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/spinlock.h> +#include <linux/efi.h> +#include <linux/percpu.h> +#include <linux/bitops.h> + +#include <asm/atomic.h> +#include <asm/cache.h> +#include <asm/current.h> +#include <asm/delay.h> +#include <asm/ia32.h> +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/machvec.h> +#include <asm/mca.h> +#include <asm/page.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/processor.h> +#include <asm/ptrace.h> +#include <asm/sal.h> +#include <asm/system.h> +#include <asm/tlbflush.h> +#include <asm/unistd.h> + +#define SMP_DEBUG 0 + +#if SMP_DEBUG +#define Dprintk(x...) printk(x) +#else +#define Dprintk(x...) +#endif + + +/* + * ITC synchronization related stuff: + */ +#define MASTER 0 +#define SLAVE (SMP_CACHE_BYTES/8) + +#define NUM_ROUNDS 64 /* magic value */ +#define NUM_ITERS 5 /* likewise */ + +static DEFINE_SPINLOCK(itc_sync_lock); +static volatile unsigned long go[SLAVE + 1]; + +#define DEBUG_ITC_SYNC 0 + +extern void __devinit calibrate_delay (void); +extern void start_ap (void); +extern unsigned long ia64_iobase; + +task_t *task_for_booting_cpu; + +/* + * State for each CPU + */ +DEFINE_PER_CPU(int, cpu_state); + +/* Bitmasks of currently online, and possible CPUs */ +cpumask_t cpu_online_map; +EXPORT_SYMBOL(cpu_online_map); +cpumask_t cpu_possible_map; +EXPORT_SYMBOL(cpu_possible_map); + +/* which logical CPU number maps to which CPU (physical APIC ID) */ +volatile int ia64_cpu_to_sapicid[NR_CPUS]; +EXPORT_SYMBOL(ia64_cpu_to_sapicid); + +static volatile cpumask_t cpu_callin_map; + +struct smp_boot_data smp_boot_data __initdata; + +unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */ + +char __initdata no_int_routing; + +unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */ + +static int __init +nointroute (char *str) +{ + no_int_routing = 1; + printk ("no_int_routing on\n"); + return 1; +} + +__setup("nointroute", nointroute); + +void +sync_master (void *arg) +{ + unsigned long flags, i; + + go[MASTER] = 0; + + local_irq_save(flags); + { + for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) { + while (!go[MASTER]); + go[MASTER] = 0; + go[SLAVE] = ia64_get_itc(); + } + } + local_irq_restore(flags); +} + +/* + * Return the number of cycles by which our itc differs from the itc on the master + * (time-keeper) CPU. A positive number indicates our itc is ahead of the master, + * negative that it is behind. + */ +static inline long +get_delta (long *rt, long *master) +{ + unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0; + unsigned long tcenter, t0, t1, tm; + long i; + + for (i = 0; i < NUM_ITERS; ++i) { + t0 = ia64_get_itc(); + go[MASTER] = 1; + while (!(tm = go[SLAVE])); + go[SLAVE] = 0; + t1 = ia64_get_itc(); + + if (t1 - t0 < best_t1 - best_t0) + best_t0 = t0, best_t1 = t1, best_tm = tm; + } + + *rt = best_t1 - best_t0; + *master = best_tm - best_t0; + + /* average best_t0 and best_t1 without overflow: */ + tcenter = (best_t0/2 + best_t1/2); + if (best_t0 % 2 + best_t1 % 2 == 2) + ++tcenter; + return tcenter - best_tm; +} + +/* + * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU + * (normally the time-keeper CPU). We use a closed loop to eliminate the possibility of + * unaccounted-for errors (such as getting a machine check in the middle of a calibration + * step). The basic idea is for the slave to ask the master what itc value it has and to + * read its own itc before and after the master responds. Each iteration gives us three + * timestamps: + * + * slave master + * + * t0 ---\ + * ---\ + * ---> + * tm + * /--- + * /--- + * t1 <--- + * + * + * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0 + * and t1. If we achieve this, the clocks are synchronized provided the interconnect + * between the slave and the master is symmetric. Even if the interconnect were + * asymmetric, we would still know that the synchronization error is smaller than the + * roundtrip latency (t0 - t1). + * + * When the interconnect is quiet and symmetric, this lets us synchronize the itc to + * within one or two cycles. However, we can only *guarantee* that the synchronization is + * accurate to within a round-trip time, which is typically in the range of several + * hundred cycles (e.g., ~500 cycles). In practice, this means that the itc's are usually + * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better + * than half a micro second or so. + */ +void +ia64_sync_itc (unsigned int master) +{ + long i, delta, adj, adjust_latency = 0, done = 0; + unsigned long flags, rt, master_time_stamp, bound; +#if DEBUG_ITC_SYNC + struct { + long rt; /* roundtrip time */ + long master; /* master's timestamp */ + long diff; /* difference between midpoint and master's timestamp */ + long lat; /* estimate of itc adjustment latency */ + } t[NUM_ROUNDS]; +#endif + + /* + * Make sure local timer ticks are disabled while we sync. If + * they were enabled, we'd have to worry about nasty issues + * like setting the ITC ahead of (or a long time before) the + * next scheduled tick. + */ + BUG_ON((ia64_get_itv() & (1 << 16)) == 0); + + go[MASTER] = 1; + + if (smp_call_function_single(master, sync_master, NULL, 1, 0) < 0) { + printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master); + return; + } + + while (go[MASTER]); /* wait for master to be ready */ + + spin_lock_irqsave(&itc_sync_lock, flags); + { + for (i = 0; i < NUM_ROUNDS; ++i) { + delta = get_delta(&rt, &master_time_stamp); + if (delta == 0) { + done = 1; /* let's lock on to this... */ + bound = rt; + } + + if (!done) { + if (i > 0) { + adjust_latency += -delta; + adj = -delta + adjust_latency/4; + } else + adj = -delta; + + ia64_set_itc(ia64_get_itc() + adj); + } +#if DEBUG_ITC_SYNC + t[i].rt = rt; + t[i].master = master_time_stamp; + t[i].diff = delta; + t[i].lat = adjust_latency/4; +#endif + } + } + spin_unlock_irqrestore(&itc_sync_lock, flags); + +#if DEBUG_ITC_SYNC + for (i = 0; i < NUM_ROUNDS; ++i) + printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n", + t[i].rt, t[i].master, t[i].diff, t[i].lat); +#endif + + printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, " + "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt); +} + +/* + * Ideally sets up per-cpu profiling hooks. Doesn't do much now... + */ +static inline void __devinit +smp_setup_percpu_timer (void) +{ +} + +static void __devinit +smp_callin (void) +{ + int cpuid, phys_id; + extern void ia64_init_itm(void); + +#ifdef CONFIG_PERFMON + extern void pfm_init_percpu(void); +#endif + + cpuid = smp_processor_id(); + phys_id = hard_smp_processor_id(); + + if (cpu_online(cpuid)) { + printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n", + phys_id, cpuid); + BUG(); + } + + lock_ipi_calllock(); + cpu_set(cpuid, cpu_online_map); + unlock_ipi_calllock(); + + smp_setup_percpu_timer(); + + ia64_mca_cmc_vector_setup(); /* Setup vector on AP */ + +#ifdef CONFIG_PERFMON + pfm_init_percpu(); +#endif + + local_irq_enable(); + + if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) { + /* + * Synchronize the ITC with the BP. Need to do this after irqs are + * enabled because ia64_sync_itc() calls smp_call_function_single(), which + * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls + * local_bh_enable(), which bugs out if irqs are not enabled... + */ + Dprintk("Going to syncup ITC with BP.\n"); + ia64_sync_itc(0); + } + + /* + * Get our bogomips. + */ + ia64_init_itm(); + calibrate_delay(); + local_cpu_data->loops_per_jiffy = loops_per_jiffy; + +#ifdef CONFIG_IA32_SUPPORT + ia32_gdt_init(); +#endif + + /* + * Allow the master to continue. + */ + cpu_set(cpuid, cpu_callin_map); + Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid); +} + + +/* + * Activate a secondary processor. head.S calls this. + */ +int __devinit +start_secondary (void *unused) +{ + /* Early console may use I/O ports */ + ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase)); + + Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id()); + efi_map_pal_code(); + cpu_init(); + smp_callin(); + + cpu_idle(); + return 0; +} + +struct pt_regs * __devinit idle_regs(struct pt_regs *regs) +{ + return NULL; +} + +struct create_idle { + struct task_struct *idle; + struct completion done; + int cpu; +}; + +void +do_fork_idle(void *_c_idle) +{ + struct create_idle *c_idle = _c_idle; + + c_idle->idle = fork_idle(c_idle->cpu); + complete(&c_idle->done); +} + +static int __devinit +do_boot_cpu (int sapicid, int cpu) +{ + int timeout; + struct create_idle c_idle = { + .cpu = cpu, + .done = COMPLETION_INITIALIZER(c_idle.done), + }; + DECLARE_WORK(work, do_fork_idle, &c_idle); + /* + * We can't use kernel_thread since we must avoid to reschedule the child. + */ + if (!keventd_up() || current_is_keventd()) + work.func(work.data); + else { + schedule_work(&work); + wait_for_completion(&c_idle.done); + } + + if (IS_ERR(c_idle.idle)) + panic("failed fork for CPU %d", cpu); + task_for_booting_cpu = c_idle.idle; + + Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid); + + platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0); + + /* + * Wait 10s total for the AP to start + */ + Dprintk("Waiting on callin_map ..."); + for (timeout = 0; timeout < 100000; timeout++) { + if (cpu_isset(cpu, cpu_callin_map)) + break; /* It has booted */ + udelay(100); + } + Dprintk("\n"); + + if (!cpu_isset(cpu, cpu_callin_map)) { + printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid); + ia64_cpu_to_sapicid[cpu] = -1; + cpu_clear(cpu, cpu_online_map); /* was set in smp_callin() */ + return -EINVAL; + } + return 0; +} + +static int __init +decay (char *str) +{ + int ticks; + get_option (&str, &ticks); + return 1; +} + +__setup("decay=", decay); + +/* + * Initialize the logical CPU number to SAPICID mapping + */ +void __init +smp_build_cpu_map (void) +{ + int sapicid, cpu, i; + int boot_cpu_id = hard_smp_processor_id(); + + for (cpu = 0; cpu < NR_CPUS; cpu++) { + ia64_cpu_to_sapicid[cpu] = -1; +#ifdef CONFIG_HOTPLUG_CPU + cpu_set(cpu, cpu_possible_map); +#endif + } + + ia64_cpu_to_sapicid[0] = boot_cpu_id; + cpus_clear(cpu_present_map); + cpu_set(0, cpu_present_map); + cpu_set(0, cpu_possible_map); + for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) { + sapicid = smp_boot_data.cpu_phys_id[i]; + if (sapicid == boot_cpu_id) + continue; + cpu_set(cpu, cpu_present_map); + cpu_set(cpu, cpu_possible_map); + ia64_cpu_to_sapicid[cpu] = sapicid; + cpu++; + } +} + +#ifdef CONFIG_NUMA + +/* on which node is each logical CPU (one cacheline even for 64 CPUs) */ +u8 cpu_to_node_map[NR_CPUS] __cacheline_aligned; +EXPORT_SYMBOL(cpu_to_node_map); +/* which logical CPUs are on which nodes */ +cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned; + +/* + * Build cpu to node mapping and initialize the per node cpu masks. + */ +void __init +build_cpu_to_node_map (void) +{ + int cpu, i, node; + + for(node=0; node<MAX_NUMNODES; node++) + cpus_clear(node_to_cpu_mask[node]); + for(cpu = 0; cpu < NR_CPUS; ++cpu) { + /* + * All Itanium NUMA platforms I know use ACPI, so maybe we + * can drop this ifdef completely. [EF] + */ +#ifdef CONFIG_ACPI_NUMA + node = -1; + for (i = 0; i < NR_CPUS; ++i) + if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) { + node = node_cpuid[i].nid; + break; + } +#else +# error Fixme: Dunno how to build CPU-to-node map. +#endif + cpu_to_node_map[cpu] = (node >= 0) ? node : 0; + if (node >= 0) + cpu_set(cpu, node_to_cpu_mask[node]); + } +} + +#endif /* CONFIG_NUMA */ + +/* + * Cycle through the APs sending Wakeup IPIs to boot each. + */ +void __init +smp_prepare_cpus (unsigned int max_cpus) +{ + int boot_cpu_id = hard_smp_processor_id(); + + /* + * Initialize the per-CPU profiling counter/multiplier + */ + + smp_setup_percpu_timer(); + + /* + * We have the boot CPU online for sure. + */ + cpu_set(0, cpu_online_map); + cpu_set(0, cpu_callin_map); + + local_cpu_data->loops_per_jiffy = loops_per_jiffy; + ia64_cpu_to_sapicid[0] = boot_cpu_id; + + printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id); + + current_thread_info()->cpu = 0; + + /* + * If SMP should be disabled, then really disable it! + */ + if (!max_cpus) { + printk(KERN_INFO "SMP mode deactivated.\n"); + cpus_clear(cpu_online_map); + cpus_clear(cpu_present_map); + cpus_clear(cpu_possible_map); + cpu_set(0, cpu_online_map); + cpu_set(0, cpu_present_map); + cpu_set(0, cpu_possible_map); + return; + } +} + +void __devinit smp_prepare_boot_cpu(void) +{ + cpu_set(smp_processor_id(), cpu_online_map); + cpu_set(smp_processor_id(), cpu_callin_map); +} + +#ifdef CONFIG_HOTPLUG_CPU +extern void fixup_irqs(void); +/* must be called with cpucontrol mutex held */ +static int __devinit cpu_enable(unsigned int cpu) +{ + per_cpu(cpu_state,cpu) = CPU_UP_PREPARE; + wmb(); + + while (!cpu_online(cpu)) + cpu_relax(); + return 0; +} + +int __cpu_disable(void) +{ + int cpu = smp_processor_id(); + + /* + * dont permit boot processor for now + */ + if (cpu == 0) + return -EBUSY; + + fixup_irqs(); + local_flush_tlb_all(); + printk ("Disabled cpu %u\n", smp_processor_id()); + return 0; +} + +void __cpu_die(unsigned int cpu) +{ + unsigned int i; + + for (i = 0; i < 100; i++) { + /* They ack this in play_dead by setting CPU_DEAD */ + if (per_cpu(cpu_state, cpu) == CPU_DEAD) + { + /* + * TBD: Enable this when physical removal + * or when we put the processor is put in + * SAL_BOOT_RENDEZ mode + * cpu_clear(cpu, cpu_callin_map); + */ + return; + } + msleep(100); + } + printk(KERN_ERR "CPU %u didn't die...\n", cpu); +} +#else /* !CONFIG_HOTPLUG_CPU */ +static int __devinit cpu_enable(unsigned int cpu) +{ + return 0; +} + +int __cpu_disable(void) +{ + return -ENOSYS; +} + +void __cpu_die(unsigned int cpu) +{ + /* We said "no" in __cpu_disable */ + BUG(); +} +#endif /* CONFIG_HOTPLUG_CPU */ + +void +smp_cpus_done (unsigned int dummy) +{ + int cpu; + unsigned long bogosum = 0; + + /* + * Allow the user to impress friends. + */ + + for (cpu = 0; cpu < NR_CPUS; cpu++) + if (cpu_online(cpu)) + bogosum += cpu_data(cpu)->loops_per_jiffy; + + printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n", + (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100); +} + +int __devinit +__cpu_up (unsigned int cpu) +{ + int ret; + int sapicid; + + sapicid = ia64_cpu_to_sapicid[cpu]; + if (sapicid == -1) + return -EINVAL; + + /* + * Already booted.. just enable and get outa idle lool + */ + if (cpu_isset(cpu, cpu_callin_map)) + { + cpu_enable(cpu); + local_irq_enable(); + while (!cpu_isset(cpu, cpu_online_map)) + mb(); + return 0; + } + /* Processor goes to start_secondary(), sets online flag */ + ret = do_boot_cpu(sapicid, cpu); + if (ret < 0) + return ret; + + return 0; +} + +/* + * Assume that CPU's have been discovered by some platform-dependent interface. For + * SoftSDV/Lion, that would be ACPI. + * + * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP(). + */ +void __init +init_smp_config(void) +{ + struct fptr { + unsigned long fp; + unsigned long gp; + } *ap_startup; + long sal_ret; + + /* Tell SAL where to drop the AP's. */ + ap_startup = (struct fptr *) start_ap; + sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ, + ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0); + if (sal_ret < 0) + printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n", + ia64_sal_strerror(sal_ret)); +} + |